A variety of charging circuits are available for charging and maintaining rechargeable batteries. Existing charging circuits typically apply a charging signal to a battery to replenish its charge. Examples of prior art circuitry used for generating such a charging signal may be found in the U.S. Pat. Nos. 4,871,959, 5,084,664, 5,063,341, 5,276,393, and 5,633,575 and U.S. Reissue Pat. No. RE35,643, the disclosures of which are hereby incorporated by reference.
For increased battery life and performance, rechargeable batteries must be protected from excessive charging voltage during recharging. Thus, the battery voltage is monitored during recharging to prevent over charging. It is known that sulphates build-up on battery plates. These sulphate deposits can damage the battery's ability to hold charge and/or be recharged. At present, charging circuits do not provide an efficient means of removal of sulphates during recharging.